As COVID-19 spreads across the country, lockdowns, school closures and cancellations of large events are taking place. These “social distancing” practices are broad policies that reduce the possibility of large-scale virus transfer and aim to slow transmission of the virus to a rate that does not overwhelm clinics, hospitals and the broader public health system. However, history shows us that these techniques are only effective in areas where transmission rates are still low — in other words, where the epidemic’s effects haven’t really been felt yet. As social distancing becomes a part of everyday life, it is important to consider that what seem to be “premature” closings are the only ones that really work — it’s a history lesson that just might save your life.

Infectious disease management is framed with respect to plagues of the past, most prominently the influenza epidemic of 1918–1919, which killed roughly 50 million people and is estimated to have infected roughly a third of the world’s population. While no vaccine was available at the time, effective public health interventions were in place that protected some communities from the epidemic’s most devastating effects. Historical studies of where and when strict social distancing policies were enacted can inform public officials on how to stop virus spread today.

In these studies, St. Louis emerged as an unlikely model of infection control through nonpharmaceutical interventions. The city applied a combination of public gathering bans and school closures before the epidemic hit the city, sparing many residents their lives. On the other hand, some cities such as Pittsburgh were more reactive in banning public gatherings and lagged even later in enforcing school closures. As a result, Pittsburgh suffered far worse from the epidemic, with a death rate almost three times as high as St. Louis. Furthermore, when implemented fully, some communities seem to have escaped mortality from the pandemic altogether.

This data shows that social distancing techniques like school closures and public gathering bans can work to mitigate the severity of an epidemic, but only if they are robust and in place before the peak of the virus’s spread.

Source:Markel H, Lipman HB, Navarro JA, Sloan A, Michalsen JR, Stern AM, Cetron MS. Nonpharmaceutical interventions implemented by US cities during the 1918–1919 influenza pandemic. JAMA. 2007 Aug. 8; 298(6): 644–54.Markel H, Stern AM, Navarro JA, Michalsen JR, Monto AS, DiGiovanni C. Nonpharmaceutical influenza mitigation strategies, US communities, 1918–1920 pandemic. Emerg Infect Dis. 2006; 12(12): 1961–1964.